The purpose of a transducer generally is to transform motion, activated mechanically, into electrical or electronic signals, which are then put to use in some form. Piezoelectric materials have been known generally to be useful in detecting motion such as acceleration of a mass, and to convert this motion into an electrical signal. U.S. Pat. No. 3,400,284 generally describes a piezoelectric accelerometer, in which piezoelectric materials are compressed to generate electrical signals in response to acceleration in a given direction, based upon the design of the device.
U.S. Pat. No. 3,701,903 adapts a piezoelectric material to react along a sensitive axis, with circuit limitations to eliminate minor changes in the mass.
The application of such a transducer used for detection of mechanical movement such as acceleration has also been applied in devices which detect motion in more than one direction. For example, U.S. Pat. No. 3,006,280 describes the application of piezoelectric transducers to fuses and provides a plurality of single direction sensors lined up in different axes in an attempt to activate a fuse for a projectile or a mine when such a device is struck or collides with another object.
None of the prior devices are truly omnidirectional in activity and are generally incapable of detecting minor seismic forces which are desired to be converted to electrical signals.